
242
ComPonent-oriented develoPment and assemblY
Persistence components are implemented using JPA entities. All the objects in the
model shown in Figure11.2 are deployed as a JAR library in the CLASSPATH.
e objects required to be persisted—TableConfig, Food, Bill, and
BillLineItem—are annotated with the JPA annotation @Entity. In addition, a
persistence.xml file in the model JAR library specifies the JPA persistence unit.
e JPA provider library is deployed along with the rest of the application, and the
business components load the JPA API objects from the CLASSPATH. In the com-
panion code, the Open JPA implementation from Apache is used as ...